Multiple circuits in same conduit - wire identification

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That Man

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I'm designing a lighting system for an industrial building. I'm considering running at least three circuits in the same conduits, and was thinking I'd specify wire colors to aid in circuit identification, but was wondering if I was running afoul of any code gotchas. There would be three separate 480V 3 phase circuits. The first circuit would be colored brn, org, yel; the second would be colored blk, red, blu; the third, emergency circuit would be colored gry, pnk, pur (I was running out of colors). Can anyone foresee any problems with this arrangement?
 
Code isn't specific about what colors can be used for ungrounded conductors, so your color choices may be valid. However there is the issue of identifying branch circuits of different voltage.

Branch Circuits Supplied from More Than One Nominal Voltage System. Where the premises wiring system has branch circuits supplied from more than one nominal voltage system, each ungrounded conductor of a branch circuit shall be identified by phase or line and system at all termination, connection, and splice points in compliance with 210.5(C)(1)(a) and (b).

Color coding is one common method of this identification, but you can use other methods. _If_ 208/120V is also present in the building, and _if_ color coding is being used to meet the identification requirements, and _if_ black,red,blue are being used for 208/120V, then you can't used them for your 480V systems.

To get more colors to work with, you might consider striped conductors. If phase doesn't matter, then you might consider making all the conductors of a single circuit one color.

-Jonathan
 
I would use only Brown, Orange and Yellow. Simple number tags are more than adequate to differentiate the different circuits. You also said emergency circuits they might not be permitted in the same raceway with normal circuits.
 
infinity said:
I would use only Brown, Orange and Yellow. Simple number tags are more than adequate to differentiate the different circuits. You also said emergency circuits they might not be permitted in the same raceway with normal circuits.
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I agree. If I saw something other than BOY, my first thought would be something else was going on besides just multiple branch circuits.
 
That Man said:
I'm designing a lighting system for an industrial building. I'm considering running at least three circuits in the same conduits, and was thinking I'd specify wire colors to aid in circuit identification, but was wondering if I was running afoul of any code gotchas. There would be three separate 480V 3 phase circuits. The first circuit would be colored brn, org, yel; the second would be colored blk, red, blu; the third, emergency circuit would be colored gry, pnk, pur (I was running out of colors). Can anyone foresee any problems with this arrangement?
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If the circuits don't require a neutral, then the color gray can't be used as it's one of the colors used for neutral.
 
Thanks for the responses folks. I would have replied earlier, but my alerts don't seem to be working, so I didn't realize you guys were on the case.

Here are some follow-up comments to address your concerns:

All hot conductors are 277V. All are single phase loads, so my revised color coding would be:

Ckt 1 phase A - brn
Ckt 1 phase B - org
Ckt 1 phase C - yel
Ckt 2 phase A - blk
Ckt 2 phase B - red
Ckt 2 phase C - blu
N for Ckt 1 & 2 - wht - just one for both. neutral currents will be almost non-existent since the circuits are closely balanced
Emergency lighting - pnk - from a UL 924 inverter, just a single 277V, not three, weird
Emergency N - gry - I wasn't sure if this could share the wht N. I don't think it's a separately derived system, but just in case

There was some concern about running emergency lighting in the same conduit. Is that a code issue or a might get called out issue? I'll run this by the client and my guys.

There was some concern about 208 elsewhere in the building precluding use of blk red blu. There is 208 in the building. These circuits never leave the lighting conduit or mingle elsewhere, but the point still stands. Again, I'll run it by the others.

I may just default back to brn org yel like some of you suggest. The reason why I was going this way at all was because on two separate occasions, I've had all the lights overhead burn out at once because contractors mis-wired the lights. And I don't go to the field very often. You all know how expensive lights are.
 
That Man said:
N for Ckt 1 & 2 - wht - just one for both. neutral currents will be almost non-existent since the circuits are closely balanced
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If these are branch circuits, see 200.4(A), you would need separate neutrals for each MWBC. If these are feeders, you are OK under 215.4.

Cheers, Wayne
 
You're posting in the NEC forum and have been given the rules, so why are you going to "run it by" anyone?
 
roger said:
You're posting in the NEC forum and have been given the rules, so why are you going to "run it by" anyone?
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Sorry? What?

So far there's been talk of a rule that precludes sharing a neutral, which I've acknowledged and accommodated. Apart from that there's been opinions as far as I can tell, and I explained my reasoning, which is pretty compelling IMO. If you'd like to point out actual code problems with what I'm thinking, please do so.
 
I think your approach violates the spirit of 210.5(C)(1) if not the letter. Technically you don't have to use wire color to identify different voltage systems but you are required to use *something* and wire color is what electricians are used to using. You cannot use black red and blue for a 480V circuit if you are using those wire colors for a 208V system elsewhere on the premises and have no other means of voltage identification. Specifying so many different colors is also a logistical headache and will likely lead to more wasted material. I would humbly suggest using brown orange and yellow for all 480V circuits and specifying a means other than wire color for individual circuit identification.
 
jaggedben said:
I think your approach violates the spirit of 210.5(C)(1) if not the letter. Technically you don't have to use wire color to identify different voltage systems but you are required to use *something* and wire color is what electricians are used to using. You cannot use black red and blue for a 480V circuit if you are using those wire colors for a 208V system elsewhere on the premises and have no other means of voltage identification. Specifying so many different colors is also a logistical headache and will likely lead to more wasted material. I would humbly suggest using brown orange and yellow for all 480V circuits and specifying a means other than wire color for individual circuit identification.
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I'm inclined to agree with you. They'll just have to figure it out in the field.
 
That Man said:
There was some concern about 208 elsewhere in the building precluding use of blk red blu. There is 208 in the building. These circuits never leave the lighting conduit or mingle elsewhere, but the point still stands. Again, I'll run it by the others.
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If Black, Red, Blue, and White have already been designated for a 208Y/120 volt system within the same building you cannot use those colors for 480Y/277 volts. As I said earlier I would just use BOY and gray.
 
infinity said:
If Black, Red, Blue, and White have already been designated for a 208Y/120 volt system within the same building you cannot use those colors for 480Y/277 volts. As I said earlier I would just use BOY and gray.
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I can't find a practical solution to prevent mis-wiring it with color codes since I'm out of standard colors, so that's what I'll end up doing. I just know it's going to happen again. Maybe not this job, but they're going to blow out all the lights. Thanks for your input. I appreciate it.
 
That Man said:
I can't find a practical solution to prevent mis-wiring it with color codes since I'm out of standard colors, so that's what I'll end up doing. I just know it's going to happen again. Maybe not this job, but they're going to blow out all the lights. Thanks for your input. I appreciate it.
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Any decent electrician should be able to pull common colored wires and number them with number tags. I get the idea of making it idiot proof with completely different colors but the NEC rules would have to be violated to do so.
 
Flip your question over.

You have a good reason for wanting to reliabily identify different 'full boats' sharing a conduit.

Ask the folk here what they find reliable and convenient for this application.

I come from the technical side of things. I tend to come up with outlandish cool solutions. (I think I did mention the availability of striped conductors :) )

Maybe you can simply order the wire "plexed" and use neutrals with different color stripes to identify circuits.

Jonathan
 
That Man said:
Sorry? What?

So far there's been talk of a rule that precludes sharing a neutral, which I've acknowledged and accommodated. Apart from that there's been opinions as far as I can tell, and I explained my reasoning, which is pretty compelling IMO. If you'd like to point out actual code problems with what I'm thinking, please do so.
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Read 210.3(C)(3) and tell us how you can use a color code for multiple voltage systems when the color code has been already been designated to one particular system.
 
That Man said:
There was some concern about running emergency lighting in the same conduit. Is that a code issue or a might get called out issue? I'll run this by the client and my guys.
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Read article 700. In this case 700.10 specifically.
 
That Man said:
I can't find a practical solution to prevent mis-wiring it with color codes since I'm out of standard colors, so that's what I'll end up doing. I just know it's going to happen again. Maybe not this job, but they're going to blow out all the lights. Thanks for your input. I appreciate it.
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Would you please fill out the information in your profile especially occupation. Thanks
 
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